In modern industrial production, often it is desirable to control the movement and locking of movable chain, strip or belt objects. Hence, there is always a demand for developing locking devices with favorable performance.
In addition, in many apparatuses, it is desirable to control the rotation of rollers. For example, in elevator systems, it is desirable to control the rotation of rollers for elevator running and stop; moreover, it is desirable to achieve instantaneous stop control. For another example, the mooring cables or anchor chains of ships are often reeled up and retracted by means of rollers, and it is often desirable to release the locking of cables or anchor chains quickly.
Particularly, for example, the seat belts on vehicles (e.g., motor vehicles) are fittings that receive wide attention, and it is of great significance to control the movement of the straps of seat belts. Owing to the sense of pressure on the user caused by the seat belts, many people don't like seat belts, and even don't wear a seat belt whenever it is possible. Even worse, to deal with compulsory checking on wearing seat belt, some users wrap the strap of seat belt slackly on their bodies by altering partial functions of the seat belt at own discretion. For example, these users pin the strap with rigid members to the vehicle body so that the strap can't be retracted, in order to avoid the sense of pressure on their bodies. Such behaviors introduce risks in the protective functions of seat belts.
The present inventor has disclosed a vehicle seat belt adjusting device in PCT Application No. WO2012/026062. The adjusting device comprises a pair of supporting swing rods composed of a first swing rod and a second swing rod and an actuator, wherein, the adjacent ends of the first and second swing rods are hinged together to form an included angle between the swing rods, one non-adjacent end of the first and second swing rods is stationary, while the other non-adjacent end moves as the included angle between the swing rod varies; the actuator applies force to the first swing rod and/or the second swing rod and/or the hinge point between the swing rods to change the included angle between the swing rods, and thereby applies variable force to the strap of the seat belt directly via the movable non-adjacent end. According to the actual requirement, the adjusting device can be designed in a way that the non-adjacent ends provide full supporting force perpendicularly on the strap and thereby restrain the strap from moving when the first swing rod and the second swing rod are in a 180° vertically aligned state. The actuator is particularly an inertia weight.
The adjusting device disclosed in the Patent Application No. WO2012/026062 can be further improved.